REAudio RTPRO12D4 12-Inch Dual 4 Ohm RT Pro Series Car Subwoofer 12" Dual 4 Ohm RT Pro Series Subwoofer Power Handling: RMS: 210 watts Mica filled polypropylene cone; Santoprene rubber surround FEA Optimized motor structure Linear conex spiders; Pressed steel basket; Spade terminals; Single magnet